Photocatalytic　N-2　fixation　involves　a　nitrogen　reduction　reaction　on　the　surface　of　the　photocatalyst　to　convert　N-2　into　ammonia.　Currently,　the　adsorption　of　N-2　is　the　limiting　step　for　the　N-2　reduction　reaction　on　the　surface　of　the　catalyst.　Based　on　the　concept　of　photocatalytic　water　splitting,　the　photocatalytic　efficiency　can　be　greatly　enhanced　by　introducing　a　co-catalyst.　In　this　report,　we　proposed　a　new　strategy,　namely,　the　loading　of　a　NiS　co-catalyst　on　CdS　nanorods　for　photocatalytic　N-2　fixation.　Theoretical　calculation　results　indicated　that　N-2　was　effectively　adsorbed　onto　the　NiS/CdS　surface.　Temperature　programmed　desorption　studies　confirmed　that　the　N-2　molecules　preferred　to　adsorb　onto　the　NiS/CdS　surface.　Linear　sweep　voltammetry　results　revealed　that　the　overpotential　of　the　N-2　reduction　reaction　was　reduced　by　loading　NiS.　Furthermore,　transient　photocurrent　and　electrochemical　impedance　spectroscopy　indicated　that　the　charge　separation　was　enhanced　by　introducing　NiS.　Photocatalytic　N-2　fixation　was　carried　out　in　the　presence　of　the　catalyst　dispersed　in　water　without　any　sacrificial　agent.　As　a　result,　1.0　wt%　NiS/CdS　achieved　an　ammonia　production　rate　of　2.8　and　1.7　mg　L　(1)　for　the　first　hour　under　full　spectrum　and　visible　light　(lambda　＞　420　nm),　respectively.　The　catalyst　demonstrated　apparent　quantum　efficiencies　of　0.76%,　0.39%　and　0.09%　at　420,　475　and　520　nm,　respectively.　This　study　provides　a　new　method　to　promote　the　photocatalytic　efficiency　of　N(2　)fixation.　(C)　2019　Science　China　Press.　Published　by　Elsevier　B.V.　and　Science　China　Press.　All　rights　reserved.